Heretofore it has been well known to provide orthodontic brackets for use in the straight-wire technique of orthodontic treatment where the archwire is generally straight and free of any bends and activated to apply forces through the construction of brackets wherein the angulation of the archwire slot and its orientation to the tooth upon which it is mounted is chosen for purposes of applying a desired corrective force. Accordingly, it has been common to use the archwire slots as a reference line for mounting in parallel relation with the occlusal plane of the mouth which thereafter through the construction of the brackets places the tie wings at an oblique angle to the reference line. This necessitates positioning the archwire slots in the tie wings such that the occlusal or gingival tie wing ends or tips may be weakened with respect to their attachment to the base portion of the bracket and which thereafter may cause failure during wearing by a patient. This is particularly evident in the use of plastic brackets which have been primarily used for purposes of aesthetics even though it is well known that a plastic bracket cannot be made as strong as a metal bracket.
Thus, cutting the slots in the tie wings at an angle such as disclosed in U.S. Pat. No. 3,477,128, where the tie wings are of equal length, will affect the integrity of the bracket.
The strength problem have referred to has been addressed in prior art brackets, such as the one disclosed in U.S. Pat. No. 4,415,330, but in this bracket the length of the tie wings is still equal and the gingival ends of the tie wings define a reference line that, while being parallel to the archwire slots, is inclined to the long axis of the tie wings such that it creates visual alignment problems when mounting the bracket on a tooth.